Electbic welding machine



March 6, 1928.

F. L. SESSIONS ELECTRIC WELDING MACHINE /mva-wram March 6, 1928.

- 1,661,970 F. L. SESSIONS ELECTRIC WELDING MACHINE Filed Jan. 13. 1923 46 March 6, 192& 1,661,970

F. L. SESSIONS ELECTRIC WELDING MACHINE Filed Jan. 13. 1923 4 Sheets-Sheet 3 w -55, if

fia 5? A lzr 27 //vv'/vT0.e.-

March 6, 1928.

F. L. SESSIONS ELECTRIC WELDING MACHINE Filed Jan. 13. 1923 4 Sheets-Sheet 4 Patented Mar. 6, 1928.

UNITED STATES PATENT," oFF- cs.

FRANK nsassrons, OF-LAKEWOOD, onro.

ELECTRIC WELDING MACHINE.

Application filed January 18, 1923. Serial No. 612,436.

My invention has to do particularly with the welding of longitudinal seamsin thinwall, metal barrels, drums, receptacles-or other elongated metal shells.

- shape shells. The edges of'th'e sheet which are 'to be welded together are generally sheared straight-before the shell is rolled up so thatthey will abut evenly when they are clamped together for welding;

Heretofore it has beencustomary to apply clamps to the metal along each side of the seam to be welded andvarious means have been proposed and used for holding and pressing the scamedges together while the welding of the seam -beenaccomplished by hand-supported and handacctylene (lame or the electric are methods of welding have-been employed in this work. 'It is a fact withinmy -personal-knowledge that the weldin of longitudinal seams of steel barrels is 'todayaceomplished -very largely by hand-welding and, although a number of' automatic 'machine welders for such articles have been proposed there are none of them, so far as I am aware, which are in successful commercial use today.

In order to successfully accomplish the welding together of the two abutting edges of a scam in thin sheet metal it is essential that certain conditions be maintained, especially asaffecting the seam-cleft in its relation-to the weld-ing agents, the'heat-supplying and seam-closing or pressure-exerting devices. This facthas been recognized by inventors in the art of welding thin-wall, metal tubing of ordinary commercial sizes ranging in thickness'of wall from about .025 to .1. inch, and of-diameters up to about three inches. Among th'eseessential' conditions are :the aceu'ra'te' alignment of the edges of thei-seam'cleft; theregular and constant speed of progression ofthe seam-cleft relative to the welding. agent;fthe accurate guiding of the seam-cleft to cause it to follow a definite path through the welding zone 'so' that both edges willlbe similarly heated, the pressing together of' the contacting surfaces of the seam at the 'welding point and the maintenance of pressure until the weld hassetpthe accurate control of the. temperature -to which the metalisraised and'the proper correlation of speed of pro- 'gression, heat supply and contact-pressure. In the welding of commercial tubing such as has been mentioned the edges of the tube bordering the seam-cleft can be readily held in accurate alignment and ressed together because of their inherent sti ness due to their 'cylindrical shape of small radius of curvaupon oppositesides 0f the tubeiat the welding throat and adjusted towards and from each other for varying the'welding pressure When, however, it comes to the welding of large diameterrthin-wa'll *slie'lls or drums" it is found that the walls of the tube adjacent guided welding devices. "Usually, the-oxythe seam cleft hat e comparatively "littleinherent stiffness and 5 it: is therefore. difficult-.4

to hold them inalig nm'entwhile they-are approaching and passing through the welding throat. It has also 'been. found/that grooved, side-pressure ,rollers, such as..are used for pressing the contacting surfaces of the seams of smalltubes-tog'etherare impractical for use with large diameters of shells, on account of theirlarge size 'a-nd weight and on account of the variation in size of the shells or drums which are tobe welded. It has also been f0und difficult to prevent the walls of large shells from'buckling and lapping along the seam-cleft, as they pass through the welding throat, thereby making an imperfect weld, or no wcld at all, so that the product has to be scrapped.

For overcoming such difiiculties as have been mentioned and to provide an apparatus inwhich large longitudinally butted seam,

' metal shells or drums may he successfully welded I make use of a flexible or yielding clamp which is-adapted to encompass the shell to be welded for the purpose ofproriding means for supporting, guiding,=aud exerting seam-closing pressure'uqmn the shell during its passage through the welding machine The flexiblejmember may be provided with suitable stifiening'ribs'to eoact with guide and prss'ure-exerting'rollers, or other devices,-an(l other prov'isions'maybe made for suitably supporting the work and for causing it to be progressively moved through the welding zone.

In other words, instead of attaching separate clamps to the shell along the abutting edges of the seam, or attempting to support the shell in n'lassive, grooved rollers, 1 provide a simple jig or appliance adapted to support the shell and to be manipulated with it in its passage throughthe welding machine.

Some of the objects of my, invention are: the provision of meansfor holding the abutting edges-of the seam cleft of a thin metal shell in proper alignment with each other and for applying pressure to the Seanras it is being welded; :theprovision of an fapparatus-=in which the welding ,of relatively large diameter, -.thin-wall cylinders ,can be performed with substantially the. same eliiciency as that with which thewelding of relatively small-diameter, thin-wall, steel tubing by oxy acetylene'or electric welding processes is ,now performed;, the provision of a flexible band or-clamp adapted to surround and form a means for supporting the shell and for-applying pressure to the seam cleft during thev welding operation; the provision of means for traversing the shell past the welding agent so that the seam may be progressively welded; the provision of a machine upon which'the unwelded-shells may be successively placed in abutting relation upon .feed rollers,;m0ved through the welding zone and delivered in welded condition; the provision of means'for guiding the seam cleft and maintaining it in proper relation to the welding agent; and the provision of means .for properly locating and aligning the flexible supporting band upon the shell to be welded. These and other objects are accomplishedby the use of my invention described in the following specification and shown in the accompanying drawings in which Fig. 1 is a plan view of a machine embodying my invention;

F ig. 2 a side elevation of the shown in Fig. 1;

Fig. 3 is a section on line IIIIII of Fig. 2;

Fig. 4 is an enlargement of a fragmentary portion of Fig. 3; v

Fig. 5 is a section on line VV of Fig. 2;

Fig. 6 is an enlargement of a fragmentary portion of Fig. 5,

machine Fig. 7 is a section on line VII-VII of.

Fig. 2;

Fig.8 is a plan view of a metal sheet from which a shell is to be made; F i 9 is a side elevation of a formed but unwe ded shell;

Fig. 10 is an end view of the unwelded shell shown in'Fig. .9;

Fig. 11 is an end view of the flexible .shown in Fig. 16;.

Fig. 18 is a vertical longitudinal section of the structure shown in Fig. 17;

Fig. 19 is a modification of the structure shown in F ig. 18 v;

- Figs. 20 and .21 are end and side views;-

respectively, on a reduced scale, of one modlficatlon of the clamp; and

- 7 Fig.22 is a sideview, on a reduced scale, .of a further modification of the clamp.

Referringto the drawings, 1 represents a pedestal forming the main support of a welding machine. An arm, 2, projects from a side of thepedestal and forms a support for the mechanism which feeds the shells past the welding means.

Above the arm, -2 ,-and paralleling it is another arm, 3, which is also supported at one end by pedestal, 1, and projects from it. In order to. better balance the arms, 2 and 3, the machine may be made with duplicate arms and mechanisms projecting from the opposite Lside of the pedestal,-l, in an obvi- .ous manner. v

-I prefer to divide the arm,,2, into two -.1Qngit-udina lly extending rails, 2, 2", which are spaced apart to accommodate vertical, supporting, feeding and guiding rolls 4, 5, 6. 7, 8pand 9, vertical, supporting, welding rolls, '10, and vertical, delivering rolls, 11. The rollsjust mentioned are supported upon suitable shafts 12, 13, 14, 15, 16, 17, 18 and 19 respectively. I have shown the roll, 4, as not being power driven but the remainder .--of the .vert-ical rolls mentioned are preferably driven by suitable means such as the ,worm drives, 20, which, as will be observed, are driven .by i shaft, 21, through suitable power transmitting connections such as the gear-5,22, 23, from a motor, 24, or other source. 0f power. Each of the rolls, 4. to 9, inclusive. -is preferably provided with an annular fin, 25, best made of saw steel and located in the median pl ane of the roll.

These fins are adapted to enter .the seam between the abutting edges which are to be .welded and to positionland guide the seam cleft as the shell travels towards and through the welding throat. For the purpo e 0 f properly "positioning the flexible clamp upon the shell I' prefer to provide llll spaeing members, 26, which may be seeured to the arm', 3, or otherwise supported just above the receiving rolls,'4, and 6. 1

The flexible clamp which I prefer'toemploy is shown in detail in Figs. '11 .to 15,

inclusive, and its position relative to the ,welding zone is best shown in .'F igs l and 6. Lpreferto make the'ela' np in the form'of a. 'band, 27, of light gaugesteeland of a length somewhat less thanth'e circumference of the shell ,which the band is to encompass,jclamp and'sfu'pport durmg 'thewelch'ng operation.

It will' be u nderstoo'd however, that I do not ,-liniit theconstruction fof the 'clamp t'o'f'the 'forn' 'shownas it is obvious:thahforjthe 'isa'lce of lightness; series Set 1 spaced apart properly engage the shell .which to be welded; :Along' ithe aliuttiiig ends of the 'fiexible hand there are' secured, preferably by riveting, trans'yerse' bail-s28, 29, which serve to" reinforeejtheedgesof the band, dis

tribute the pressuremf the lateral-pressure "rolls and form flangesortrack's, 28, 29",

' be understood that while the"bars,' 28 29, 'Lextend"transversely of the band, '27, such upon which the lateral-pressure rolls, 30, 31,

traversed pastthe welding. agent. It will 'direction isparallel to the direetion of movement'of the shell through theiwi 'elding machine. i

The members of the pairs of lateral-presisure rolls, 30 to' 3 t inelnsive} are disposed u1')o n'op )os1te sides of the seam of the shell to be welded, and upon opposite s des of the median plane of the vertical rolls, 4 toll, inclusive, theaxesof these lateral pressure rolls being preferably vertical or so disposed that their pressu'renpon the bars 28, 29, is transmittedto the edges of the seam cleft in Y a direction substantially tangent to the shell at the seam cleft and normal. to the,con'tacting'surfaees which are to be welded. It will be seen that the flexible clamp, 27,

exerts a. substantially uniform, circumferential pressurc upon the shell during its passage through the machine, thispressure causing the edges of the seam Cleft to firmly contact with eachbthenand to be welded together by the weldingheat which is preferahly'applied'in or close to t-he plane of the axes-of one oft-he pairs, 33, oflateral-pressure rolls. f

-Th'e lateral-pressure rolls, 30 to 34, inelusire, arepreferablyp'ower driven by suitable means such as the-worm drives 35,36, 37, 3S

j and 39 to which power' may be transmitted from the motor, 24, by means of suitable v v v Y purpose the rolls,. 133, i iistead o'f bein'glplain 32,' 33 and'fi t press 'and'roll' along as the "shell, encompassedfbyftlieiband, '27, is

" 1922, in which: the-'eleetrodesare. supported in bearings earriediby the transformer and the weight of the transforiner' is u'tilized to press the'e'leetrodeslintojeontacthvith the 4 York: I. A "1 2.0 I;-.'-.; B5

" Instead 0f laii eleetrie' welding device a gas torch such as the oiry acetylene"torch, 48, shown millfig, may he;ernployedf oi 'Weld- 'mg the; seamt' If a' gas-name instead 'of electric eurrent be nsed'for heating-the metal '90 at the seam cleft suitablep'rovision may be n'iade for holding dow'iithe edges 'of the shell adjacentto the pointwheretheweldmg flame impinges upon the metal. I For'this faced as shown mf F d'may -have annular shoulderjsiiadaptdfto' engage ahd hold downfth jipp'er'edgesfof the bars, 28,

29, as. shown at "133, Fig. "'161 It will 'be,. noted that, *Figf16 fwhere gas 1 welding fl is illustrated,'ft he bars, 128 and29, iii-ephemtogether than'they are in Figs. 3, {and 6.

Thisjis'foi' tliepurpose: o f'll oldingthe edges of the seam cleft iii aeeuratetahgnmentat the welding point. hen the electrical re-"ios sistanee method of welding is used the .-eleetrodes, l5 and 46,. bear downwardly upon the edges of the shell upon opposite'sides of the seam cleft and no.0ther means for holding down the shell edges is requircd.'110 Supplemental vertical pressure rolls such as those shown at 60 inFig. 17 may be cinployed when the welding agent is a gas flame or the electric .arc.

For supporting the edges of the shell'ad-iil; jaeent the seam cleft when electric welding is employed, the roll,'10, is preferably u'iarle in two parts insulated from eaeh other and from theirsnpporh This may be a'eeomplished by means of an insulating'disiflio such as that shown at -19 (Figs; 3 and 4), for insulating the rolls from each other, and

the 'iii'sul'at ing'bushing,- 50, and insulating wash rs, 5 1, for insulating the roll, 10, from the frame'fof thelma chine. j

Insteadof usingfatwo-part metal roll, 10, with insulation; 49"," between the parts, a roller support, 10", of suitable insulating material maybe used and the disc, 49, be

dispensed with. It will be understood that 130 terial rolls, 10 or 10, be made of, and whatever the heating means for effecting the weld, it is preferable to provide an annular groove 49 in the surface of such rolls to permit the \veldburr, if any there .be, to

inq rolls.

Ilor preventing the distortion, buckling or lapping from expansion due to heat of the edges of the seam cleft as they approach the welding zone a top pressure roll, 52, maybe adjustablyimou nted aboveithe rol1, 9. The roll, 52, is preferably provided with a circumferential slot adapted to'receivefthe annular fin, 25, of roll, 9. :T he roll, 9, is preferably mounted to have lateral play between the supports, 2 and 2", spaces, 9 (Fig. 5) being provided to permit such lateral play.

The slotted roll, 52, is referably adjustable both vertically-and aterally, the vertical adjustments being providedfor the purpose of properly positioning the roll 52,

to suitably engage different thicknesses of metal being-welded, and the lateral adjustments being provided for thepurpose of pro erly positioning the seam cleft to .cause it a ways to pass through the weldin fzone' centrally betwe n the'electrodes if ,e lectric resistance-welding be employed, or in proper alignment with the welding flame or are, respectively if gas or electric-arc-welding be employed. The roll, 52, is .supportedin a bracket, 52, which is vertically adjustable in a guide block, 52" by means of a screw and hand wheel, 52. The guide block'52", is laterally adjustable in a sliding guide in a stationary support, 52, by means of a screw and hand wheel, 52. It will be seen that both vertical and lateral adjustments of roll, 52, may be etfected by the mechanism described. If desired the guidin fin may be omitted from roll, 9, and a similar fin be incorporated in roll, 52. In such case a slot should be provided in roll, 9, to receive the fin of roll, 52. It is obvious that means other than that herein shown and described may be employed for guiding the seam of the shell as itapproaches the welding point and I do not limit. my invention to the use of any par ticular form of scam guide.

For supporting the outer end of the arm, 3, suitable floor posts or pedestals, 53, 54, may be employed.

In Fig. 8 there is shown a plan view of a sheet, 55, from which the shell to be welded may be formed. It will be understood that the ed es of this sheet should be properly squared vup and that the sheet should be of suitable length to form the desired girth of 9 and 10 the sheet, 55, is shown after it has been rolled into ,a cylindrical, open-seam shell, the edges, 55, 55", being shown slightly spaced apart-but in abutting relation.

' It will understood that the clamp, 27, should be of suitable length or circumference tp properly encompass the shell, and, when passed between" the lateral-pressure "lens, '30, 31, 32; 33;;and'34, to exert proper extend into it without striking thesupport- 57. Zflhe jshaftS, 58; of the lateral-pressure ndy-15 s ppo te i e t g adjustgably mountedjn the side'frames,,59, which B mani ulat ng the screws 56,57, the l a 'pr 'sl r' frqll a s yb 'm d e e theesi l'r l i p? rs, 2 t0 guidethe shell the seam cleft tog er. th 'w lidin r'sin The operatioii'fof 'njiy'invention is as followsz f"; f;

I A ne talshell suoh as -.that shown in Figs.

9 an .10'is ped into a flexible clamp 27, the .oppositefe es of the shell being placed f I 9'- 9 ghl1 pa l l the rs,. 9, s e; v.e y;and t .e endieq al distan t ere'fr6m-,,'Tlishellind band are then sprungopen about as the-bandis shown to rung inEig. '11,' and together they are lifted vertically up'ffroin beneath arm, 2, and {the 'edgesof the ,s hel l, 'an d the bars, 28, 29, of the'band are madeto engage the fins, 25, of rolls} and 5, and the spacin members,2 6, respectively. Thejshell with the encompassing band is then 1 pushed toward the -welding"throat until the shoulders-28, 29, areengaged by the first pair, 30, of lateral-pressure rolls when it is seized by them and propelled toward the welding throat. As it travels along it is successively engaged by the pairs ofrolls, 31, 32, 33, and '34, guided by the fins, 25, of the vertical rolls, 6, 7, 8 and 9 and finally after the seam is welded it is delivered 'by vertical rolls, 11 and lateral rolls, 34. It will be understood that separate shells encompassed by separate flexible bands may be successively placed upon the machine so that the leading end of each shell abuts against thetrailing end of .the preceding shell, the seam'clefts being welded in continuous succession as though they were alljormed in one piece. For such a continuous succession of shells, the clamps, 27, should beimad e' slightly narrower than the shells-asshowninFig; 15.

Aniong theadvantages of my invention are increased output, saving of factory/space, and standardized and superior quality of weld. .In addition to these advantages-my invention efiects a very considerable saving in the cost of welding thin-wall'shells pM- .ticularlyas it provides means for utilizing ..I,1 1 ay be. form part of the arm,

in the making of such shells of relatively large diameter, which method is the most economical method of seam-welding at present known.

I'cla'im:

1 In apparatus for welding the contact ing surfaces of a longitudinal, open scam in a metal shell, a freely suspended detachable yielding clamp adapted to encompass the shell, said clamp being shorter in length than the circumference of said shell to provide aspace between the ends of the clamp, said clamp provided with stifl'ening flanges substantiall the width of thecla-mp and being adapte to co-a-ct with lateral-pressure devices for causing said clamp to exert circumlferential pressure upon the encompassed shel.

:2., In apparatus of the class described, .a freely 'suspended detachable yielding clamp ada'ited to enco'mpa ss a metal shell, a scamwel ing device, and means for causing a metahshell, encompassed by said clamp, to progressively traverse the welding zone of said seam-welding device.

,3..In apparatus of the class described, a freely suspended detachable yielding clamp rolls, one of-said rolls being in contactwith one and the othcr'in contact with the other of said flanges.

'7. In apparatus of the classdeseribcd, a

yielding clamp adapted to encompass" a metal shell, said clamp being shorter in c rcumterence. than the circumference of said shell to provide a space between the/ends of the clamp, said "clamp. having a transverse flange upon eac'li'of its endsgadapte d' to form a track'for and'co act"withflateralf compassed shell, a pair of oppositely dis posed, lateral-pressure rolls" adapted to roll along said flanges, means ioriprogressively traversing said shell, encompassed "by s'a 1d clamp, in a'straight line past said later adapted to encompass a, butted-seam, metal -pressure rolls, one 'o f-said rolls being in shell, 0. seam-welding device, and means for causing progressive, relative movement of such' a shell, encompassed by said clamp, and said seam-Welding device, whereby the seam of saidshell is progressively subjected to thenvelding action of said seam-welding device..

4.1111 apparatus of the class described, a yielding clamp adapted to encompass a metal shell, said clamp having a transverse flange -upon each of its ends, a seam-welding device, means for supporting and progressively traversing an open-seam, metal shell, encompassed by said clamp, throughthe welding zone of said seam-welding dcvicc, and means adapted to engage said flanges and exert pressure thereon to cause said clamp to circumfcrentially compress said shell and press the abutting scam surfaces thereof together.

1n apparatus of the class described, a yielding clamp adapted to encompass a metal shell, said clamp being shorter in circumference than the circumference of said shell to provide a space betwen the ends of the clamp, said clamp having a transverse flange upon each of its ends adapted to form a track for and oo-act with lateral-pressure roll; for causing said clamp to exert circumferential pressure upon the encompassed shell.

6. In apparatus of the class described, a yielding clamp adapted to encompass a metal shell, said clamp being shorter in circumference than the circumference of said shell to provide a space between the ends of the clamp, said clamp having a transverse with the cthercfs aid flanges, arid"l ieat'ing said shell in said space, to ajwel'ding temperature as 'the shell I and itsfjclamp aref'so traversed. I

,8..-In a machine forweldingmetal barrels, a -support, a plurality ct aligned jvertical rolls carried by shaftssupported-on said support means ton-driving somej'of said rolls, a second support above said first named support, a plurality of horizontal rolls mounted upon shafts carried by said second support,'said horizontal rolls being arran ed in pairs, the members of a p air being, isper-zed upon opposite sides of the median verlical plane of said vertical rolls, spacing members supported above said vertical rolls in said vertical plane, said vertical and horizontal rolls'bei'ng disposed in two series in planes transverse to eachother, a welding agent disposed near the end of said series of rolls, a flexible clamp adapted to encompass a shell to 'bc welded, sald' clamp being adapted to be placed upon said vertical rolls with its ends abutting said spacing members, to be traversed along the topsof said verticalrolls, held in alignment thereby and by said horizontal rolls, and caused-to pass said welding agent.

9. In a machine of the class described a cantalever support, vertical rolls carried by said support, said rolls being provided with annular fins,saicl fins being disposed in aligm ment with each other, a pluralityS of horizontal rolls above said vertical r0 in pairs, the members of a pair being disdisposed posted upon opposite sides of said fins, a welding agent in the plane of said fins, clamping means adapted to support and guide a shell to bewelded, said clamp being adapted to move'u'pon the tops of said vertical rolls and be guided by said horizontal rolls past said welding agent.

, 10, 'In a welding machine of theclass described, a cantaleve r support, a plurality of rollers carried thereon having their axes transverse to said'su'pp'ort and'theirperipheries extending above the surface of said support, a plurality of guide rolls Supported upon vertical axes above said-support, said guide rolls being' ar1 'anged in pairs, the members of a pair being disposed upon opposite sides of the median vertical planeofsaid 'i-ollers, a flexible, shell-supporting clamp, said rollers 'beim adapted to engage saidelai'np as it is cause to move longitudinallyoisaid support supported upon said roll'ers.,.'.

.11. ,Ida'pparatuspf the class described. a

. fleixiblei clampf tadalpted to encompass a 1 buried-seam, metal s ell, means for support-- ing and imparting progressive movement to su'cha shell, encompassed by said clam said movement being parallel to said butte seam, nieans engaging said clamp adapted to exert pressure thereon to circumferentially compress said shell andpress the abutting seamsurfacesthereof tdgethebfand heating means in the path of movement of said seam adapt- .ed to heat said abutting seam-surfaces there- 'of"to aQwelded' temperature, whereby they arewelded together.

1 2. 'Inapparatusof the class described, a flexible clamp adapted to encompass a metal shell,'sai"dclariip having a transverse flange upon each eras; ends, an overhanging sup port adz 1ptecl.to be encompassed by a metal shell and clamp, 21 vertical roll carried by "said support and having its periphery rojecting above the support to form a roller bearing for "said shell, a pair of oppositely disposed transverse rolls supported above said support and adapted to engage said flanges, means for causing'thel shell encompassed by said clamp to progressively move along upon said vertical roll, said fianges respectively engaging said transverse rolls, and heating means disposed to heat the metal of said shell between said flanges to a welding temperature-as theshell is progressively moved past said heating means.

13. I n apparatus of the class described, a flexible clamp adapted to 'encompass'a metal shell, said clamp having a transverse flange upon ea cli of its ends, an overhanging support adapted to be encompassed by a metal shell and said elamp, avertical roll carried by said jsupportand having its periphery projecting above the support to form a roller bearinglfor said shell, a pair of oppositely disposed transverse rolls supported above said support and adapted to engage said flanges, means for causing the shell encompassed by said clamp to pro ressively move along upon said vertical ro ll, said flanges respectively en aging said transverse rolls, heating means disposed to heat the metal of said shell between said flanges to a Welding temperature as the shell is progressively moved'p'ast said heating means, and'means for varying the distance between said transverse rolls.

14. In apparatus of the class described, an overhanging horizontal support provided with vertical rolls alongits upper surface said support'and rolls adapted to be encompassed by and supportan elongated metal shell, a flexible clamp adapted to en'- compass such a metal shell saidclamp being shorter in circumference than the circumference of said shell to prov de a space be-' tween the ends of 'the clamp, said clamp being adapted to e'o-act with lateral pressure" devices for causing said clamp to e'xertciifcumferential pressure upon the encompassed shell, means for causing'progressive move ment of said shell and said clampbetween said lateral pressure devices and along said" support, and heating means adapted to heat the metal ofsaid shell between the ends of said clamp to a welding temperature.

15. In apparatus of the class described, means-for supporting a shell having 111 longi moved, means co-actingwith saidyieldin means to-cause it to exertcir cu mferen'tial pressure upon the shell to'press the abutting seam-surfaces thereof together; and heating means in the path of movement of said seam adapted to heat said abutting seam-surfaces to a welding temperature whereby they are welded together.

16. In apparatus of the class described, means for supporting a shell'having a longitudinal, open seam and for causing it to progressively move in a direction parallel to said seam, circumferentially yielding means adapted to encompass the shell and expose the seam thereof as 'it is so supported and moved, means co-acting with said yielding means to cause it to exert circumferential pressure upon the shell to press the abutting seam-surfaces thereof together, heating means in the path of movement of 'said seam adapted'to heat said abutting seam-surfaces to a welding temperature whereby they are welded together, and a seam guide "between said abutting seam surfaces ata point in advance of said heating means.

17. In apparatus of the class described, a series of aligned, vertical rolls provided with hearings in an elongated support adapted to be encompassed by an open-scam shell disposed with its abutting seam-surfaces separated by said fins, a yielding clamp adapted to encompass said shell and expose the seam thereof, means eo-acting with said clamp to cause said clamp to exert circumferential pressure upon said shell to close the seam thereof, heating means adapted to heat the abutting surfaces of said seam to a weldingtemperature, and means for causing progressiverelative movement of said shell 'and said heating means longitudinally.

of said seam.

18. In=apparatus of theclass described, a

series'of aligned, vertical rolls one ofthem being provided with .an annular fin, said rolls being mounted in hearings in an elongatedzsupport adapted to be encompassed by an open-seam shell disposed 'with its inner seam-edges resting on said rolls and its abutting seam-surfaces separated by said iin a yielding clamp adapted to encompass said shell and expose the seam thereof, lateralpressure meansco-aeting with said clamp to .k cause it to exert circum'lerentml pressure upon said shell to closethe seam thereof, heating-means adapted-to heat the abutting surfaces of said seam to a weldin temperature, "'and means :rmcausing; progressive,

relative movement of said shell and said of said seam to a welding tempeniture,

means for causing progressive, relative movement, parallel to said seam,- of said shell, encompassed by said yielding means, and said heating means, and means co-acting with said yielding means to: cause it to exert circumferential pressure upon the shell. to press the abutting'seam-surfaces thereof together during said progressive movement whereby they are progressively Welded.

20.- In apparatus of the class described, means for supporting a shell having a longitudinal open seam, circumferentially yielding means adapted'to engage the shell and expose the seam thereof as it is so supported, means coacting with said yielding means to cause it to exert pressure upon the shell to press the abutting seam surfaces thereof togethnheating means, means to cause relative longitudinal movement between the yielding means and the heating means, said heating means arranged to heat said abut ting seam surfaces during said movement to a welding temperature and thereby weld said seam. 4

21. In apparatus of the class described, an overhanging support adapted to be loosely encompassed by and support an elongatedmetal shell having a longitudinal seam, means for pressing the abutting edges of said seam together, welding means adjacent to said shell adaptedto apply welding heat to. the metal thereof along said seam, and means for causing relative progressive traversing movement between said shellandsaid welding means to cause said seam to be. progressively welded. 1 4

. 22. In apparatusof the class described, an overhanging support adapted tobe] loosely encompassed by and suppojrtE-an,elongated metal .shell having a longitudinal seam, means adjustable circumferentially toengage said shell while exposing-said seam, means cooperating with the circumferential engaging means for pressing the abutting edges of said seam togetheig we'lding means adjacent to said shell adapted to apply welding heatvto the metal thereof along said seam, and means -for causing relative progressive. traversing movement between said shell and said welding means to cause said seam to-be progressively welded.

.23. In, apparatus :for progressively butt welding the contacting-surfaces o.f.,a longitudinal openseamin a metal shell, a yielding clamp-adapted .to substantially encompassthe shell, said clamp; having a transverse flange upon each of its ends, and means for progressively exerting pressure upon said flanges to progressively force the surfaces of the seam-cleft of the shell together.

24. In apparatus for progressively butt welding the contacting surfaces of a longi. tudinal open seam in a metal shell, a yielding clamp adapted to substantialy encompass the shell, means for contracting said clamp aboutsaid shell to cause the abutting contacting surfaces of the seam-cleft to be pressed together, welding means adapted to heat the contacting surfaces of the sean1- cleft in a narrow zone to welding temperature, and means for causing relative traversing movement longitudinally ofthe welding means and said clamp and of the, seam of said shell whereby said seam is progressively heated and welded.

[25. In apparatus for progressively butt welding a longitudinal seam in a metal shell, an elongatedsupport adapted to be loosely encompassed byand to support the shell sus-' pended thereon and contacting therewith upon oppositesides of the seam-cleft of said shell, means for pressing the abutting surfaces of the seam-cleft together, heating means adapted to heat a short length of said abutting surfaces to a welding temperature and means for causing progressive, relative traversing movement of said shell and said welding means to cause said seam to be progressively welded.

26. In apparatus of the class described, means for supporting a shell having a. longitudinal butted seam, circumferentially yielding means adapted to encompass the shell and expose the seam thereof as it is so supported, means coacting with said ielding means to cause it to exert circum erential pressure upon the shell to press the abutting seam-surfaces together, heating means adapted to heat a narrow area of said abutting seam-surlaces to a welding temperature and means for causing progressive relative traversing movement of said shell and said heating means to cause saidv seam to be progressively welded.

27. In apparatus for progressively, electrically welding the contacting surfaces of a longitudinal, butted scam in a 'metal shell by the electrical resistance method, an elongated support adapted to be loosely encom' passed by and to support the shell suspended thereon and contacting therewith upon op posite sides of the seam-cleft of said shell and closely adjacent thereto, means for pressing the abutting-surfaces of the seamcleft together, an electric welding circuit including electrodes adapted to contact with the metalof said shell upon opposite sides of the seam-cleft respectively and-closely adjacent thereto whereby the pressure of the electrodes upon the-shell is transmitted to and supported by said elongated support and means for causing progressive, relative traversing movement of said shell and said electrodes to cause said seam to be progres sively welded.

28. In apparatus for butt-welding the edges of a shell comprising an independent and detachable, yielding, shell-engaging and enveloping means having reinforced edges and adapted to support said shell and expose the shell edges to be welded, pressure applying means adapted to engage said reinforced edges to press the shell edges into butt contact, heating means adapted to heat a narrow area of the contacting edges of the shell to a .welding temperature, and means for causing progressive relative traversing movement of said shell and said heating means to cause the contacting edges of said shell to be progressively welded together.

29. In apparatus of the class described, means for supporting a shell having a longitudinal butted seam, circumferentially yielding means adapted to encompass the shell and expose the seam thereof as it is so supported, means co-acting with the said yielding means to cause circumferential pressure to be applied to the shell to press the abutted seam surfaces together, heating means adapted to heat a narrow area of said abutting surfaces to a welding temperature, and means for causing progressive relative travversing movement of said shell and said heating means to cause said seam to be progressively welded, said yielding means being adapted to prevent the .welded joint from separating.

30. In apparatus of the class described, a non-attached yielding clamp adapted-to encompass a metal shell, a seam-weldin device, means for supporting and progressively traversing a, metal shell encompassed bysaid clamp through the welding zone of said seam-welding device, and means adapted to engage said clamp and exert pressure thereon to'ca-use said clamp to circumferentially compress said shell and press the seam surfaces thereof together. I

31. In an apparatus of the class described, a non-attached clamp adapted to encompass a metal shell and of outer dimensions substantially the width-of the shell, said clamp being shorter in circumference than the circumference of said-shell to thereby provide a space between the ends of the cla'mp'so as to expose the shell to the action of a welding means. 1 I

32. In an apparatus of the class described, a freely suspendable non-attached clamp adapted to encompass a metal shell, said clamp having a circumference shorter than the shell to be encompassed, and transverse flanges thereon extending substantially the width of the clamp. i

33. In apparatus for progressively electrically butt-welding the contacting surfacesof a butted seam in sheet metal, a detachable encompassing clamp, means for supporting said sheet metal and clamp upon opposite sides of the seam cleft closely adjacent there'- to, electrodes disposed above and separated from said supporting means and adapted to contact with the sheet metal plates upon opposite sides of the seam-cleft and closely adjacent thereto and substantially in the vertical planes of contact of the sheet metal work with said supportingmeans, means for guiding and traversing said sheet metal work and clamp past said supporting means and said electrodes longitudinally of the seam-cleft, means for causingthe electrodes to press firmly upon the work, means for pressing the abutting surfaces of the seamcleft firmly together, and an electric circuit including said electrodes whereby electric current is caused to flow across said seamcleft between said electrodes and progressively weld said seam-cleft. I

In testimony whereof, I aflix my signature.

FRANK L. SESSIONS. 

